1. Field of the Invention
The present invention relates generally to the field of presses, and more particularly, to presses with structures for providing an adjustable pinch point guard.
2. Background of the Invention
It is frequently necessary to have a pinch point guard covering an area to prevent pinching between a roll and another element. But a problem arises because using an area pinch point guard that covers a whole print area prevents cleaning the printing plate or diecut plate without stopping the press.
Briefly, one embodiment of the invention comprises a press with a capability to adjust for multiple roll diameters, comprising: a frame; a mounting assembly with at least one adjusting arm for mounting a roll therein, the adjusting arm being moveable to change position relative to the frame in correspondence to a change in diameter of the roll; a guard assembly that provides a guard across a pinch point between a roll and another element, the guard assembly being moveably attached to the at least one adjusting arm and to a portion of the frame to automatically adjust a position of the guard when the at least one adjusting arm is moved in order to maintain a spacing between the guard and the roll within a predetermined range.
In a further embodiment of the present invention, the guard assembly is automatically adjusted to also maintain a spacing between the guard and the other element within a predetermined range.
In a further embodiment of the present invention, the guard comprises a guard bar.
In a further embodiment of the present invention, the guard assembly comprises at least one guard arm for holding said guard, with at least one guard arm being pivotally attached at one part thereof to a pivot axis on said at least one adjusting arm, and attached at a second point adjacent to the guard via a guide slot.
In a further embodiment of the present invention, there are two adjustment arms in the mounting assembly and two guard arms in the guard assembly, with each guard arm pivotally attached to a different one of the adjustment arms.
In a further embodiment of the present invention, the guard arm has substantially the shape of an S.
In a further embodiment of the present invention, the guide slot is a radial slot centered on an anilox roll.
In a further embodiment of the present invention, guide slot is disposed in the frame.
In a further embodiment of the present invention, the guard arm comprises at least two pieces.
In a further embodiment of the present invention, the mounting assembly is moved by a power element.
In a further embodiment of the present invention, the press is a printing press.
In a further embodiment of the present invention, the press is a diecutter.
In a further embodiment of the present invention, a method is provided for adjusting pinch point guard in a press, comprising the steps of: moving a mounting assembly for a roll relative to a frame in correspondence to a change in diameter of the roll; and automatically moving a guard bar in unison with the movement of the mounting assembly to adjust a position of the guard bar to automatically maintain a spacing between the guard bar and the roll and between the guard and another element within a predetermined range.
In a further embodiment of the present invention, the step of automatically moving a guard bar comprises causing the guard bar to follow a radial motion.